A TiO₂-modified porous carbon fiber interlayer for long-term cycling and high-rate lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) are increasingly viewed as promising alternatives to traditional lithium-ion batteries. However, their practical application is hindered by challenges such as polysulfide shuttling and the slow kinetics of sulfur redox reactions. Herein, we have developed an interlayer composed of titanium dioxide nanoparticle-modified porous carbon fibers (TiO₂-PCF), created through the carbonization of facial tissue. The high polarity and excellent electrolyte wettability of TiO₂-PCF significantly enhance the electrochemical performance of the sulfur cathode. Notably, it achieves a high initial capacity of 1492 mA h g⁻¹ at 0.1C, demonstrates a minimal decay rate of 0.11% over 200 cycles at 0.5C, and maintains a high capacity of 554 mA h g⁻¹ at 2C. This study presents an effective approach to markedly enhance the performance of the sulfur cathode, providing essential insights for future advancements in LSBs.